Marrocco says he's happy and amazed to have new arms. He has prosthetic legs but says that without arms, he felt "kind of lost for a while."

The procedure was only the seventh double-hand or double-arm transplant ever conducted in the United States.

The infantryman was injured by a roadside bomb in 2009.

The New York City man also received bone marrow from the same dead donor to minimize the medicine needed to prevent rejection.

The 13-hour operation on Dec. 18 was led by Dr. W.P. Andrew Lee, plastic surgery chief at Hopkins.

Marrocco was being released from the hospital Tuesday but will receive intensive therapy for two years at Hopkins and then at Walter Reed National Military Medical Center in Bethesda.

After a major surgery, human nerves regenerate at a rate of an inch per month, Lee said.

"The progress will be slow, but the outcome will be rewarding," he added.

Dr. James Higgins is the Chief of the Curtis National Hand Center at MedStar Union Memorial Hospital. He tells WBAL Radio that it is a great day for Brendan and for transplantation.

Higgins was part of the transplant team that operated on Marrocco back in December. He says the fact that Brendan went forward and discussed it in public is a great benefit for other wounded warriors that may not be aware of the opportunities available to them. "Brendan has been a great spokesperson for the program and I think he will make people more aware of just how far science and surgery have come and what opportunities are available for these people that have given so much for our country," says Higgins.